He and Nationals manager Davey Johnson both were ejected on a wild afternoon.

The Pirates had won four games in a row, but they couldn't finish off a sweep of the Nationals.

One problem was trying to overcome what Hurdle called "our worst inning on the field this season."

Briefly breaking out of a slump that had seen it score a total of 13 runs while going 0-6 since the All-Star break, Washington batted around to go ahead 4-0 against A.J. Burnett after one inning. First baseman Gaby Sanchez, second baseman Jordy Mercer and third baseman Pedro Alvarez each committed an error, meaning only one run was earned.

After Burnett hit Harper with a pitch, Steve Lombardozzi followed with a bunt single. Harper strayed too far off second, getting caught in a rundown. But shortstop Clint Barmes' throw got past Alvarez, who was charged with an error. That allowed Harper to come all the way around to score, and Lombardozzi wound up on second. Ryan Zimmerman's opposite-field single made it 2-0.

Two outs later, Ian Desmond, who missed Wednesday's game because of a burst blister on his left palm, singled. And Denard Span, struggling so much he was dropped from the leadoff spot to No. 7 in the batting order, singled to right. Two runs scored on the play, making it 4-0, because of Sanchez's throwing error.

The next batter, Kurt Suzuki, reached on Mercer's fielding mistake, making it the first time since July 4, 2011, against Houston, that the Pirates made three errors in an inning.

Took that kind of sloppiness for the Nationals' slumbering offense to wake up.

Still, the Pirates made a game of it despite twice trailing by four runs. In the ninth, Nationals closer Rafael Soriano was charged with four runs while getting only one out. Soriano walked the first two batters, then gave up Mercer's run-scoring double and Russell Martin's RBI single, Pittsburgh's first hits of the day with runners in scoring position.

Nationals bench coach Randy Knorr, who took over after Johnson was tossed in the fifth, then lifted Soriano and turned to rookie Ian Krol (1-0). A walk loaded the bases, and Josh Harrison - who homered earlier - tied the game with a two-run single.

But in the ninth, Harper delivered the first game-ending homer of his career, putting a pitch from Morris (4-4) over the wall just to the left of straightaway center.

"I was attacking him with it, and he put a good swing on it," Morris said, "and he hit to the deepest part of the park."

Harper raised his right fist overhead as he rounded first base and was mobbed by a bouncing pack of teammates as he reached home plate.

It was his 14th homer of the season, and first since July 1, the day he came off the disabled list after missing time with a left knee injury.

"Great to get the 'W' today. We really needed it," said Harper, who sat out Wednesday because of the bothersome knee. "Hopefully this one will carry on into tomorrow and the next day."

Johnson left the game when he came out of the dugout while Desmond was arguing a called third strike. Hurdle got ejected in the seventh after Alvarez was thrown out at first while veering too far toward second base after a single.

It was that kind of game.

"It looked, for me, like he was looking to check the ball - if it was going to go through, into the outfield. Once he didn't see it go through, stay in the infield ... he squared right up and ran through the bag," Hurdle said. "So that was argument."

NOTES: Burnett wound up going seven innings, allowing only one earned run. ... Pirates RHP Vic Black made his major league debut, entering with two outs in the eighth. ... Gonzalez's 11 strikeouts equaled his career high. ... The Pirates open a three-game series at Miami on Friday, with Pittsburgh LHP Jeff Locke (9-2, 2.11) starting against RHP Henderson Alvarez (0-1, 3.28).